The Relative Layout doesn't cover the width of the screen

Question

I'm making an application that uses the relative layout to create a transparent black activity on the screen but the layout that it creates doesn't fit with the width of my phone screen.

Here's the result from my coding

Here's my xml file.

<?xml version="1.0" encoding="utf-8"?>
<RelativeLayout
    xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:app="http://schemas.android.com/apk/res-auto"
    xmlns:tools="http://schemas.android.com/tools"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    >

    <RelativeLayout
        android:layout_width="match_parent"
        android:layout_height="match_parent"
        android:background="#A6000000"
        >

    </RelativeLayout>
</RelativeLayout>

Here's the styles.xml that I use to create transparent activity

<style name="Theme.Transparent" parent = "android:Theme">
        <item name="android:windowIsTranslucent">true</item>
        <item name="android:windowBackground">@android:color/transparent</item>
        <item name="android:windowContentOverlay">@null</item>
        <item name="android:windowNoTitle">true</item>
        <item name="android:windowIsFloating">false</item>
        <item name="android:backgroundDimEnabled">false</item>
    </style>

I have already set match_parent for both width and height. Thank you.

Answer 1

You need to set this in your styles.xml for your Theme.Transparent:

<item name="android:windowIsFloating">false</item>

A floating window is usually a dialog, so has automatic spacing on either side. Setting this to false removes this automatic spacing. You can read a bit more about it in the related documentation, specifically:

... whether this window is being displayed with a floating style (based on the R.attr.windowIsFloating attribute in the style/theme).

Although, if you're doing a fullscreen RelativeLayout, one wonders why you need transparency after all..!